Effectiveness of Three Sampling Approaches for Optimizing Mapping and Preventive Chemotherapy against Schistosoma mansoni in the Western Part of Côte d'Ivoire.

The elimination of schistosomiasis as a public health problem by 2030 is one of the main goals put forth in the World Health Organization's roadmap for neglected tropical diseases. This study aimed to compare different sampling approaches to guide mapping and preventive chemotherapy. A cross-sectional parasitological survey was conducted from August to September 2022 in the health districts of Biankouma, Ouaninou, and Touba in the western part of Côte d'Ivoire. The prevalence and intensity of Schistosoma mansoni infection were assessed in children aged 5-14 years using three sampling approaches. The first approach involved a random selection of 50% of the villages in the health districts. The second approach involved a random selection of half of the villages selected in approach 1, thus constituting 25% of the villages in the health district. The third approach consisted of randomly selecting 15 villages from villages selected by approach 2 in each health district. The overall prevalence of S. mansoni was 23.5% (95% confidence interval (CI): 19.9-27.6%), 21.6% (95% CI: 17.1-26.8%), and 18.3% (95% CI: 11.9-27.1%) with the first, second, and third approach, respectively. The respective geometric mean S. mansoni infection intensity was 117.9 eggs per gram of stool (EPG) (95% CI: 109.3-127.3 EPG), 104.6 EPG (95% CI: 93.8-116.6 EPG), and 94.6 EPG (95% CI 79.5-112.7 EPG). We conclude that, although randomly sampling up to 50% of villages in a health district provides more precise population-based prevalence and intensity measures of S. mansoni, randomly selecting only 15 villages in a district characterized by low heterogeneity provides reasonable estimates and is less costly.

Genetic characterization of schistosome species from cattle in Côte d'Ivoire.

BACKGROUND: Schistosomiasis is a water-based parasitic disease that affects humans, livestock and wild animals. While considerable resources are dedicated to the surveillance, disease mapping, control and elimination of human schistosomiasis, this is not the case for livestock schistosomiasis. Indeed, there are important data and knowledge gaps concerning the species present, population genetic diversity, infection prevalence, morbidity and economic impact. This study aimed to identify circulating schistosome species in cattle across Côte d'Ivoire and to investigate their population diversity and structuring. METHODS: Overall, 400 adult schistosomes were collected from slaughtered cattle at six sites across Côte d'Ivoire. Additionally, 114 miracidia were collected from live cattle at one site: Ferkessédougou, in the northern part of Côte d'Ivoire. DNA from all specimens was extracted and the cox1 and ITS1/2 regions amplified and analysed to confirm species. The genetic diversity and structuring of the schistosome populations were investigated using 12 microsatellite markers. RESULTS: All adult schistosomes and miracidia presented Schistosoma bovis mitochondrial cox1 profile. Nuclear ITS1/2 data were obtained from 101 adult schistosomes and four miracidia, all of which presented an S. bovis profile. Genetic diversity indices revealed a deficiency of heterozygotes and signals of inbreeding across all sites, while structure analyses displayed little geographic structuring and differentiation. Cattle in Côte d'Ivoire thus appear to be mono-species infected with S. bovis. Hybrids of Schistosoma haematobium × S. bovis have not been identified in this study. Cattle schistosomes appear to be panmictic across the country. CONCLUSIONS: Our results contribute to a deeper understanding of schistosome populations in Ivorian cattle and emphasize a One Health approach of joint human and animal surveillance and prevention and control programmes for schistosomiasis.

Prevalence and risk factors of schistosomiasis and hookworm infection in seasonal transmission settings in northern Côte d'Ivoire: A cross-sectional study.

BACKGROUND: Schistosomiasis and hookworm infection remain public health problems in large parts of sub-Saharan Africa. The epidemiology of schistosomiasis and hookworm was studied in seasonal transmission settings in the northern part of Côte d'Ivoire. METHODOLOGY: In August 2018, a cross-sectional study was conducted. Urine and stool samples were collected from 742 individuals aged 6-96 years in 16 localities from four departments in northern Côte d'Ivoire. Urine samples were examined by a filtration method for quantification of Schistosoma haematobium eggs. Stool samples were subjected to duplicate Kato-Katz thick smears and eggs of Schistosoma mansoni and soil-transmitted helminths (STHs) were counted. Additionally, a questionnaire was administered to determine demographic characteristics and to identify risk factors of schistosomiasis and STHs. Malacologic surveys were carried out at water points that are contacted by humans and animals. PRINCIPAL FINDINGS: The prevalence of schistosomiasis was very low. Only two cases of S. mansoni were found (0.3%, 95% confidence interval [CI]: 0.1-1.0%). The distribution of S. haematobium was focal, with cases found only in two departments; Ferkessédougou (5.4%, 95% CI: 2.5-9.9%) and Ouangolodougou (2.7%, 95% CI: 0.9-6.3%). Hookworm was the only STH species observed with a prevalence of 1.5% (95% CI: 0.8-2.8%). A higher risk of S. haematobium infection was observed in males compared to females, but the difference was not statistically significant (2.3% versus 1.3%, odds ratio [OR]: 1.5, 95% CI: 0.8-2.7). Participants aged 16-20 years showed the highest prevalence of S. haematobium. A total of 111 human- and animal-water contact points were identified at 47 water sources. Three potential intermediate host snails of schistosomes were collected; namely, Bulinus forskalii (n = 761), Bulinus truncatus (n = 205), and Biomphalaria pfeifferi (n = 1). Yet, only one specimen of Bu. truncatus was found to be shedding schistosome cercariae. CONCLUSIONS/SIGNIFICANCE: This study confirms very low transmission of schistosomiasis and hookworm in northern Côte d'Ivoire. The establishment and rigorous implementation of integrated surveillance-response systems could lead to the elimination of schistosomiasis and hookworm in this part of Côte d'Ivoire.

Efficacy of triclabendazole and albendazole against Fasciola spp. infection in cattle in Côte d'Ivoire: a randomised blinded trial.

Triclabendazole is the anthelminthic of choice for the treatment of fascioliasis, however, it is only registered in a few countries. We investigated the efficacy of a single-dose of triclabendazole (12 mg/kg) or albendazole (15 mg/kg) against Fasciola spp. infection in cattle on farms in the northern part of Côte d'Ivoire in a randomized clinical trial. Faecal samples were obtained from 196 cattle, of which 155 (79.1%) were found positive for Fasciola spp. by the sedimentation technique. Cattle infected with Fasciola spp. were randomly allocated (3:3:1) to receive triclabendazole (n = 66), albendazole (n = 67) or left untreated to serve as control (n = 22). Follow-up faecal samples were collected on days 21, 28, 90 and 188 post-treatment. No adverse events were observed as reported by farmers in any of the treatment groups. The proportion of non-egg shedding cattle, assessed at day 21 (primary outcome), was significantly higher in cattle treated with triclabendazole (95.4%) compared to those receiving albendazole (70.3%; odds ratio [OR] 8.73, 95% confidence interval [CI] 2.43-31.28, p <0.001). The egg reduction rate (ERR) expressed as number of eggs per gram of faeces, a secondary endpoint assessed at day 21 post-treatment, was significantly higher in the triclabendazole arm (arithmetic mean (AM) ERR = 99.8%) than in the albendazole arm (AM ERR = 92.2%), with a difference of 7.6%-points (95% CI: 0.9-14.5%-points, p=0.026). This is the first report of efficacy of triclabendazole against Fasciola spp. in naturally infected cattle in Côte d'Ivoire. Our results confirm that triclabendazole is the most effective treatment of fascioliasis and therefore, should be considered for the control of livestock fascioliasis; if resources allow in combination with intermediate host snail control and raising farmers awareness of pasture and livestock management to avoid reinfection.

Prevalence and distribution of livestock schistosomiasis and fascioliasis in Côte d'Ivoire: results from a cross-sectional survey.

BACKGROUND: Schistosoma and Fasciola are zoonotic parasites of public health and veterinary importance. However, while the epidemiology of schistosomiasis in humans is well studied, little is known about fascioliasis and schistosomiasis in livestock in Côte d'Ivoire. This study aimed to determine the prevalence and the distribution of livestock schistosomiasis and fascioliasis across Côte d'Ivoire. In 2018, we conducted a cross-sectional survey in abattoirs and farms in 13 departments of Côte d'Ivoire. In abattoirs, the mesenteric veins and livers of slaughtered cattle, sheep and goats were examined for adult Schistosoma and Fasciola flukes. Faeces from live cattle, goats and sheep were collected and examined for Schistosoma and Fasciola eggs using a sedimentation technique. RESULTS: A total of 386 cattle, 174 goats and 151 sheep from abattoirs and 435 cattle, 22 goats and 176 sheep from farms were sampled. The observed prevalence of schistosomiasis was higher in slaughtered animals. Fascioliasis was more prevalent in farm animals. The prevalence of schistosomiasis in slaughtered cattle varied between 5.9% (95% confidence interval (CI): 0.7-19.7%) and 53.3% (95% CI: 37.9-68.3%) with the highest prevalence observed in Ouangolodougou in the North. Cattle from farms had a relatively low prevalence of schistosomiasis, with the highest prevalence found in Ouangolodougou (2.4%, 95% CI: 0.7-6.1%). The prevalence of fascioliasis varied considerably from one department to another, ranging from nil (95% CI: 0.0-18.5%) to 50.8% (95% CI: 43.4-58.2%), with the highest prevalence found in farm cattle in Dikodougou in the North. Sheep and goats had a lower prevalence of schistosomiasis and fascioliasis than cattle. In slaughtered animals, cattle aged 4 years and older were at highest risk for schistosomiasis (odds ratio (OR): 2.4; 95% CI: 1.0-5.6) and fascioliasis (OR: 2.1; 95% CI: 1.1-3.9). In farm animals, male cattle had higher odds of being infected with Schistosoma (OR: 4.3; 95% CI: 0.7-26.9) than females. CONCLUSIONS: Our study confirms that schistosomiasis and fascioliasis are endemic in livestock across Côte d'Ivoire. A strategic control programme should be considered, especially for cattle, including providing drinking water in troughs to reduce faecal contamination of water sources by cattle.

Accuracy of the sedimentation and filtration methods for the diagnosis of schistosomiasis in cattle.

Infection with blood flukes of the genus Schistosoma causes considerable human and animal morbidity, mortality and economic loss to the livestock industry. Current diagnostic tools have limitations. In this study, we compared the sedimentation and filtration methods for the diagnosis of schistosomiasis in livestock. A total of 196 faecal samples from cattle in Côte d'Ivoire were subjected to sedimentation and filtration for the diagnosis of schistosomiasis and other intestinal parasite infections. Schistosoma eggs or miracidia were discovered in 32 samples: 15 by filtration only, seven by sedimentation only, six concurrently by both methods and four by observing miracidia swimming on the sedimentation slide. The sensitivity of sedimentation and filtration was 41% and 66%, respectively. Cases with no Schistosoma eggs identified in the sediment but miracidia swimming on the slide indicate that eggs had hatched before microscopy. More accurate diagnostic are required for livestock schistosomiasis, in order to better understand the epidemiology and inform control and elimination efforts in livestock and human populations.